ABSTRACT. The palm tree juçara (Euterpe edulis Mart) is considered one of the most important and threatened native species in the Atlantic Forest. The search for juçara seeds (Euterpe edulis Martius) has increased, generating a need for technologies favorable to their production, quality and conservation. The aim of this study was to describe the seed germination patterns of 45 juçara accessions by using a nonlinear model to examine the behavior of these patterns and select superior genotypes. After clustering 45 juçara accessions into four groups, four nonlinear models, namely, the logistic, Gompertz, von Bertalanffy and Weibull models, were tested based on their fit for each group of accessions. The Gompertz model presented the best fit to describe the germination growth curve of E. edulis seeds. Groups 3 and 4 presented the highest daily germination rates and were considered the most vigorous. Analysis of deviance was performed, revealing genetic variability among the genotypes in terms of seed germination and vigor. It was possible to find a nonlinear model that best explained our data, and this model may also be a promising model for other palm tree species. It is possible to select genotypes based on the characters we analyzed, due to the elevated genetic variability.

Abstract Euterpe edulis is an endemic species of the Atlantic Forest that is threatened by the unsustainable exploitation of palm heart. Fruit management is an alternative to overcome this problem, promoting income generation, preserving the trees in forest remnants and motivating the implementation of farms for commercial production. In this study, the genetic diversity and structure of four natural populations of E. edulis were evaluated using microsatellite markers and six morphological fruit traits, analyzed with and without the REML/BLUP method. The longitudinal diameter had the strongest influence on the differentiation of genotypes. The genetic differentiation among populations was low and inbreeding was detected within populations among sites. Molecular and morphological data indicated high genetic diversity in the E. edulis populations. The REML/BLUP analysis increased the accuracy of morphology-based estimates of genetic diversity, thus contributing to improve breeding strategies for fruit quality and genetic conservation by use in E. edulis.

RESUMO A palmeira Euterpe edulis é uma espécie nativa da Mata Atlântica e atualmente se encontra na lista das espécies ameaçadas de extinção. Uma alternativa para retirá-la desta lista seria o estímulo para o plantio comercial, focando o manejo dos frutos, que recebem a classificação de “superfruta” pelas suas propriedades químicas e nutricionais. Entretanto, uma etapa de extrema importância que precede a seleção de genótipos superiores é o estudo das associações entre as variáveis, pois permite traçar estratégias de seleção alternativas para maximizar os ganhos. O presente trabalho teve por objetivos estimar as correlações genéticas pelo procedimento REML/BLUP e os efeitos diretos e indiretos sobre a massa dos frutos, por meio da análise de trilha, para seis caracteres de frutos de 198 acessos de E. edulis. Foram analisados frutos de 198 genótipos de juçara coletados em 20 fragmentos florestais na região Sul e Caparaó do Estado do Espírito Santo. De cada genótipo, avaliaram-se 25 frutos para as características: diâmetro longitudinal e equatorial do fruto e da semente; e massa do fruto e da semente. Os dados obtidos foram utilizados para a estimativa das correlações genéticas através do método de máxima verossimilhança restrita e melhor predição linear não viesada (REML/BLUP). Posteriormente, as correlações genéticas entre as variáveis de fruto foram submetidas à análise de trilha. Os seis caracteres de fruto estudados apresentam associação genética positiva com magnitude superior a 0,71 pelo procedimento REML/BLUP. O diâmetro longitudinal do fruto e a massa das sementes possuem maior efeito direto sobre a massa dos frutos, o que as torna mais indicadas para aumentar as chances de sucesso na seleção de genótipos de juçara com frutos maiores. As características diâmetro longitudinal do fruto e a massa das sementes são as principais determinantes das variações na massa dos frutos.

ABSTRACT The palm tree Euterpe edulis is a native species from Mata Atlântica and it is nowadays found in the list of species which are threatened by extinction. One option to withdraw it from this list would be the stimulation of the commercial planting aiming the management of fruits which receive the “super fruit” classification by their chemical and nutritional properties. However, one stage of extreme importance that precedes the superior genotypes selection is the study of associations among the variables, because it allows delineating alternate selection strategies to maximize the gains. The present study had as objective to estimate the genetic correlations by the REML/BLUP procedure and the direct and indirect effects upon fruit mass by path analysis for six fruit characters of 198 accessions of E. edulis. Fruits of 198 Juçara genotypes collected in 20 forestry fragments in the south and Caparaó region of the state of Espírito Santo were analyzed. From each genotype 25 fruits were evaluated for the characteristics: longitudinal and equatorial fruit and seed diameter; fruit and seed mass. The obtained data were used for genetic correlations estimative through the method of restricted maximum likelihood and better unbiased linear prediction (REM/BLUP). Subsequently, the genetic correlations among the fruit variables were submitted to path analysis. The six fruit characters studied show positive genetic association with magnitude higher than 0.71 by the REML/BLUP procedure. The longitudinal diameter of fruit and seed mass have greater direct effect on fruit weight, which makes them most indicated to increase the chances of success in the Juçara genotypes selection with larger fruit . The characteristics longitudinal diameter of fruit and the seed mass are the main determinants of changes in the mass of fruit.